Vascular leiomyomas are benign tumors arising from the muscular layers of veins. Here, we discuss a case of Vascular leiomyoma of the right knee which was misdiagnosed as an epidermoid cyst on ultrasonography. Treatment usually consists of excision and these swellings rarely recur. It is important therefore to consider vascular leiomyomas as a differential diagnosis for swellings in the subcutaneous tissue especially in the extremities.